Researchers say the ageing effect of a smile stems from people’s inability to ignore the wrinkles that form around the eyes during smiling.

A new study finds smiling can make you look two years older than you are. (Shutterstock)

If you care about how old you look, it might be a good idea to keep a poker face. A new study says smiling can make you appear to be two years older than you are.

The study has been published in the journal Psychonomic Bulletin and Review.

“We associate smiling with positive values and youth,” said study co-author Melvyn Goodale, director of the Brain and Mind Institute at Western University. “Think of all the skincare and toothpaste companies that sell the same idea every day.”

But this study – in which researchers flashed images of people with smiling, neutral and surprised expressions – showed the opposite: participants perceived the surprised faces as the youngest and smiling faces the oldest.

During the study, researchers flashed images of people with smiling, neutral and surprised expressions. Participants perceived the surprised faces as the youngest and smiling faces as the oldest.
(Shutterstock)

“The striking thing was that when we asked participants afterwards about their perceptions, they erroneously recalled that they had identified smiling faces as the youngest ones,” Goodale said.

“They were completely blind to the fact they had ‘aged’ the happy-looking faces. Their perceptions and their beliefs were polar opposites.”

Goodale said the ageing effect of a smile stems from people’s inability to ignore the wrinkles that form around the eyes during smiling. A look of surprise, on the other hand, smooths any wrinkles.

“It may seem counter-intuitive, but the study shows that people can sincerely believe one thing and then behave in a completely different way,” Goodale said.